2001 GMC Yukon XL (SLT) transmission

[DieselMonk]

I had a 2000 Yukon XL 3/4ton 4x4 with a 4L80E tranny and a 6.0L gasser engine. If you have the 4L80E tranny and she shifts fine and there are no extra rpms while she is in overdrive (for example going up a hill rising rpms without shifting back) you are fine. I had to exchange the tranny in this truck after 65 thousand km, not miles, as it was shot and reverted to emergency mode. The replacement cost 6500 CAD which 3000$ paid GM (good will) and I paid 3500 CAD. If there is that symptom, you got about another 30tkm before she fails.

 

[jinman]

Just checking on potential repair of the transmissions. The figures I am seeing are $3500-$3900!! Wow. Nothing wrong with it right now that I know of. . .

. . .However these things are so expensive I don't know how anyone feels comfortable making the purchase. Heck, even the smaller Acadia 2WD has a sticker of $45K. I just can't go there.

I'm with you, Alan. I bought my first house (1200 sq ft on 1/2 acre) for $25k in 1970. If was not a new house. My buddy bought a brand new house about the same footage for $27k. The point I'm making is that it is hard for me to spend as much on a new car as I did on a house back then. To spend twice as much is out of the question.

I've posted about this before, but my truck's transmission was slipping and acting like it was on its last leg. I had it overhauled at 160k miles due to similar symptoms and was looking at spending the money for another overhaul. After reading extensively online, I went out and disconnected the battery for 45 minutes to cause the ECM/PCM (engine control/power control module) to reset and reboot. Suddenly, the transmission worked like a new one. So, even if your transmission starts to shift erratically and act up, be sure it is not the computer control module that has had a software crash and needs a reboot. Heck, even things like a dirty throttle position sensor can cause all kinds of havoc with engine and transmission operation. Our "drive by wire" vehicles can sure lead us off on a tangent if we let them.

 

[Alan L.]

We have another road trip lined up for August. I plan to change the transmission fluid again but this time not the flush but rather drop the pan and change the filter. Thinking of things that might quit on me at 190K miles I am thinking of having the u-joints and wheel bearings at least checked out, and changing out the radiator hoses. What about changing out the water pump and thermostat since these things rarely even last the 190K miles? Does that make any sense?

 

[jinman]

Alan, I would not go so far as to change anything that seemed to be okay. I'd look closely at the hoses, especially heater hoses and short loops on the engine for age cracking and getting hard. Most every hose leak I have ever had was in a heater hose close to the engine where the hose was exposed to high heat and was hard as a rock. If you water pump and thermostat seem to be working fine, I would not touch them. The more work you get done, the more likely a mechanic will accidently introduce something that will fail. I think your model is likely to have plenty of spare parts at almost any auto parts store since it is a GM. So, I'd go ahead and have the check the u-joints for tightness and the wheel bearings, but only replace deteriorated hoses that are hard and cracking. I'd leave the waterpump and thermostat alone, but check the serpentine belt for cracks. Also, does your model have electric fans or a fan on a clutch attached to the water pump? If you have a fan clutch, you want to make sure the clutch operation is smooth and not wobbly. Sometimes old fan clutches can lock up and not spin when the engine is cool. Those will eat lots of fuel and kill your mileage. Most likely you have electric fans. If they are tight and work well, then I would not worry about them either.

 

[Alan L.]

I checked out under the hood just now. The fan clutch seems normal, can move it easily but enough resistance that it doesn't spin. Not wobbly at all. Hoses all look fine. Surpentine belt looks fine and was replaced maybe 35K miles ago. No sign of any leaks of any kind under the hood.

 

[Kyle_in_Tex]

Alan, listen closely to every component on your serpentine belt. Especially the tensioner and pulley bearings. Either bearing can leave you stranded. Fortunately, these are such common vehicles that most auto parts carry all the high failure rate parts. My '99 Sub had a bunch of stuff go wrong from 130K to 155K miles. It was paid off but it seemed like I was making payments on it again for about a year. Since I've had most everything major repaired, it has been a pretty decent vehicle since.

 

[crashz]

Between 150K and 170K I did the water pump, hoses and belts on my 04 GMC 1/2 ton. The water pump was actually fine, but I found that the little metal gaskets at the ports were leaking due to corrosion. I felt it was a good time to do the water pump as well.

Wheel bearings on 4x4s go intermittantly. I did 3 of them on the passenger side of the GMC and two on the drivers side. But this truck also plowed snow. Expected casualty.

The only actual surprise was the alternator. Left me on a job site. Fortuantely, its easy job to change and I was up and runnning in 1/2 hour after a co-worker brought me to a parts store.

I changed the transmission fluid (pan drained only) every oil change (most times anyway) and greased the frontend. When I traded the truck at 179K miles, the original frontend and transmission were working fine.

 

[Alan L.]

Well, I went ahead and got this work done - replaced upper and lower radiator hoses, thermostat, flushed and changed out the coolant, fuel filer replaced again. They inspected the brakes, wheel bearings, water pump, front end components, and u-joints and said everything looked fine. Pressure tested the cooling system. Using a stethescope the mechanic listened to various systems and said he did detect a little noise in the transfer case that was not detectable with the naked ear. However he said it should have lots of miles left on it and shouldn't be a problem any time soon.

A GM mechanic online recommended the thermostat be replaced every 5 years, but that the water pump should be fine if its not leaking or making noise.

Reading some of these other posts now I worry about alternator and idler pulley. Also the A/C system. All seems fine right now so I guess I'll cross my fingers.

Plan to put on two new tires and get them rotated and balanced plus front end alignment next week.

 

[jinman]

Alan, all I'd say now is enjoy your trip. I think you've done more than most would do, and you'll have a very pleasant trip with no problems.

 

[Soundguy]

i agree... probably overplanned.. but heck.. if it feels good.. go with it